combat arms website>>support>>customer service>>big blu button labled customer service or something similar>>login to your nexon account>>click submit a ticket>>fill out the form>>Press send>>thank me
i think u posted this somewhere else too
also try letting the page fully load before clicking earn free NX it worked for me,
this is the 2nd time someone asked this i think it was you...
[Hej-edit]
Dont double post!